BIOL 1408 Midterm Review

Biology

The scientific study of life.

Cells

The basic units of life enclosed by a plasma membrane.

Eukaryotic Cells

have a nucleus and organelles

Homeostasis

The ability of an organism to maintain internal stability.

Nucleotides

The monomer subunits composing nucleic acids like DNA and RNA.

Gene Expression (Central Dogma)

The flow of genetic info from DNA to RNA to protein.

Evolution Contributors

Charles Darwin and Alfred Russell Wallace independently proposed natural selection.

Natural Selection & Adaptations

Traits enhancing survival become common; adaptations are inherited traits aiding survival.

Mutations

Changes in the nucleotide sequence of DNA providing genetic variation.

Extinction

The complete disappearance of a species from Earth.

Levels of Biological Organization

Organs, organ systems, population, community, ecosystem, and biosphere.

Phylogenetic Tree

A branching diagram showing evolutionary relationships among species.

Three Domains of Life (BAE)

Bacteria, Archaea, and Eukarya.

Taxonomy Binomial System

Two-part naming: Genus (capitalized and italicized) and species (italicized only).

Scientific Method Steps

Observation, question, hypothesis, prediction, experiment, and conclusion.

Scientific Repeatability

Experiments must be repeatable and results communicated for peer validation.

Chemical Reactions

Processes breaking and forming chemical bonds to create new substances.

CHON in Living Organisms

The four most common elements: Carbon, Hydrogen, Oxygen, and Nitrogen.

Subatomic Particles

Protons (positive, nucleus), neutrons (neutral, nucleus), electrons (negative, orbitals).

Atomic Mass vs. Atomic Number

Atomic number is proton count; atomic mass is protons plus neutrons.

Calculating Mass Number

Add the number of protons and neutrons together.

Types of Chemical Bonds

Nonpolar covalent, polar covalent, ionic, and hydrogen bonds.

Isotopes

Atoms of the same element with different numbers of neutrons.

Solvent and Solution

A _______ dissolves solutes to form a homogeneous mixture called a _______.

Specific Heat of Water

Water's high specific heat resists changes in temperature.

Heat of Vaporization

The high energy required to convert liquid water into gas, aiding cooling.

Ice vs. Liquid Water Density

Ice is less dense than liquid water because molecules spread out in a lattice.

Acids, Bases, and pH

Acids release H+ ions; bases release OH- ions or accept H+ ions.

Organic vs. Inorganic Molecules

Organic molecules contain carbon-hydrogen bonds; inorganic molecules generally do not.

Monomers vs. Polymers

Monomers are small building blocks; polymers are long chains of monomers.

Dehydration vs. Hydrolysis

Dehydration builds polymers by removing water; hydrolysis breaks them using water.

Functional Groups

Specific groups of atoms attached to carbon skeletons that determine chemical reactivity.

Carbohydrates

Sugars providing energy; monomers are monosaccharides like glucose.

Lipids

Hydrophobic molecules like fats and oils used for long-term energy and membranes.

Proteins

Polymers of amino acids performing structural, enzymatic, and regulatory functions.

Nucleic Acids

Polymers like DNA and RNA composed of nucleotide monomers storing genetic info.

Cell Theory & Robert Hooke

All living things are made of cells; Hooke discovered cells in 1665.

Basic Cell Attributes

All cells exchange nutrients and share a plasma membrane, cytoplasm, and DNA.

DNA vs. RNA in Cells

DNA is permanent genetic storage; RNA temporarily carries instructions for protein synthesis.

Prokaryotic Cell Features

Small, simple cells lacking a membrane-bound nucleus and organelles.

Eukaryotic vs. Plant/Animal Cells

Eukaryotes have organelles; plant cells have cell walls and chloroplasts, animal cells do not.

Fluid Mosaic Model

Describes the cell membrane as a fluid lipid bilayer with embedded mobile proteins.

Phospholipid Structure

Composed of a hydrophilic head and two hydrophobic tails forming bilayers.

Temperature & Membrane Fluidity

Higher temperatures increase membrane fluidity; lower temperatures decrease it.

Selectively Permeable

A property allowing certain molecules to pass while blocking others.

Membrane Protein Categories

Enzymes, recognition, receptor, connection, and transport proteins.

Solute, Solvent, and Gradient

Solutes dissolve in solvents; a gradient is a difference in concentration across space.

Diffusion and Osmosis

Diffusion moves solutes down a concentration gradient; osmosis is the diffusion of water.

Tonicity (Isotonic, Hypertonic, Hypotonic)

Compares solute concentrations; hypertonic shrinks cells, hypotonic swells them.

Passive Transport

Movement across membranes without energy using simple or facilitated diffusion.

Active Transport & Endocytosis/Exocytosis

Active transport uses energy to move substances; endocytosis/exocytosis transport bulk materials.

prokaryotic cells

a single-celled life form that does not have a distinct nucleus or other membrane-bound parts

DNA

stores genetic info

RNA

aids protein synthesis

Genes

genes are DNA segments

Genome

the _______ is complete DNA.

Unicellular Organisms

organisms consist of a single cell;

Multicellular Organisms

organisms have many cells.

Elements

pure substances

Compounds

combined elements

Molecules

bonded atoms

Valence Electrons

Make up the outer shell

Electronegativity

an atom's pull on electrons.

Chemical Bonds: Single bonds

share one electron pair

Chemical Double bonds

share two electron pairs

Cohesion

water molecules sticking together

Surface Tension

resistance to stretching.

Adhesion

water sticking to other surfaces

Capillary Action

moves water upward

Hydrophobic

molecules repel water

Hydrophilic

molecules are attracted to water